header{
    display: block;
    margin: 0 auto;
    width: 100%;
    text-align: center;
}

header #newgamebutton{
    display: block;
    margin: 10px auto;
    width: 100px;
    padding: 10px 10px;
    background-color: pink;
    color:white;
    border-radius:10px;
    text-decoration:none;
    outline: none;
    font-size: 16px;
}
header #newgamebutton:hover{
    background-color: peachpuff;
}

header p{
    font-size: 25px;
    margin: 10px auto;
}

#grid-container{
    width: 460px;
    height: 460px;
    padding: 20px;
    margin: 10px auto;
    background-color: #bbada0;
    border-radius: 10px;
    position: relative;
}
.grid-cell{
    width: 100px;
    height: 100px;
    border-radius: 6px;
    background-color: #ccc0b3;
    position: absolute;
}

.number-cell{
    border-radius: 6px;
    font-weight: bold;
    font-size: 60px;
    line-height: 100px;
    text-align: center;
    position:absolute;
}